1. Field of the Invention
The present invention relates, generally, to windshield wiper systems. More specifically, the present invention relates to a breakaway mounting bracket assembly for a wiper system that displaces a portion of the wiper system below the impact line of a vehicle upon receipt of a predetermined load such as during a vehicle-pedestrian impact.
2. Description of the Related Art
Impacts between vehicles and pedestrians are a concern for automakers. In order to minimize the likelihood of vehicle-pedestrian impacts, OEMs provide automobiles including safety features such as anti-lock brakes and traction control systems. However, such features do little to reduce the severity of injury to a pedestrian should such an impact occur.
Nevertheless, there is an ongoing evaluation of the designs of automobiles in an effort to reduce the severity of injury to a pedestrian upon impact with a vehicle. Specifically, OEMs have begun to evaluate what is commonly referred to as an “impact line” of a vehicle. A vehicle's impact line is defined by points of contact made by a pedestrian upon impact of a vehicle. As a result of the different makes and models of automobiles as well as the physical features of a pedestrian, the impact line can vary. However, despite these variances, the region where the hood meets with the windshield is a common point of contact on virtually all impact lines. This region is commonly referred to as the “engine plenum” and is often where components of windshield wiper systems are located.
Windshield wiper systems commonly include a wiper assembly that contacts the surface to be wiped, a wiper arm that supports the wiper assembly as it moves across the surface to be wiped, and a linkage assembly having a pivot shaft assembly that interconnects the wiper arm assembly to a drive mechanism. The pivot shaft assembly transfers movement of the linkage assembly to the wiper arm. Due to its role in facilitating movement of the wiper arm, the pivot shaft assembly is operatively connected to several moving components of the linkage assembly and therefore complex to assemble and repair, if necessary. Furthermore, the pivot shaft assembly and the wiper arm are often operatively connected together at or above the impact line for a vehicle-pedestrian impact and therefore presents a risk of causing greater injury to pedestrians upon impact when compared to vehicle components located below the impact line.
In an attempt to reduce the number of wiper system components located above the impact line, windshield wiper systems in the related art have been proposed that include a pivot shaft assembly that retreats into the engine plenum upon application of a load to the wiper arm. Specifically, when subject to a predetermined load, the pivot shaft assembly separates from either the wiper arm or other components of the linkage assembly. However, since the pivot shaft assembly operatively connects several moving parts of the wiper system, repairing the damaged wiper system can be complex and costly. Further, since the severable pivot shaft assembly directly receives the load, false positives may be incurred. A false positive occurs when the pivot shaft retreats into the engine plenum upon application of a load other than that resulting from vehicle-pedestrian impact. By way of example, a false positive may be incurred during replacement of wiper assemblies.
As a result, there is a need in the art for a windshield wiper system that presents a reduced risk of increasing injury to pedestrians during a vehicle-pedestrian impact. Accordingly, there is a need in the art for a wiper system having components that retreat below the impact line upon receipt of a predetermined load but that is cost-effective and simple to repair. Furthermore, there is a need in the art for a wiper system having components that retreat below the impact line upon receipt of a predetermined load and that reduces the likelihood of false positives.